Humanizing Healthcare – Human Factors for Medical Device Design

Preface
	References
Acknowledgments
Abbreviations
Contents
About the Authors
Chapter 1: Introduction
	1.1 Medical Error
	1.2 Medical Devices
	1.3 What Is Human Factors Engineering?
		Goals of Human Factors Engineering
		What Human Factors Engineering Is Not
		Benefits of Human Factors Engineering
	Resources
	References
Chapter 2: Qualitative Human Factors Research Methods
	2.1 Human-Centered Design
	2.2 Human Factors Research
	2.3 Reliability and Validity
	2.4 Selecting Research Participants
	2.5 Ethical Standards
	2.6 Literature Review
	2.7 Case Study
	2.8 Naturalistic Observation
	2.9 Design Ethnography
	2.10 Interviewing
		Structured Interview
		Semi-Structured Interview
		Unstructured Interviews
		Interview Questions
		Ensuring Interviews Are Productive
	2.11 Focus Groups
		In-Person Focus Groups (Synchronous, Co-Located)
		Remote (Online) Focus Groups (Synchronous, Distributed)
		Bulletin Board (Online) Focus Groups (Asynchronous, Distributed)
	2.12 Diary Studies
	2.13 Critical Incident Technique
	2.14 Participatory Design
	2.15 Contextual Inquiry
	2.16 Analyzing Qualitative Data
		Overview
		Task Analysis
		Swimlanes
		Journey Maps
		Scenarios
		User Profile
		Prototyping
	Resources
	References
Chapter 3: Quantitative Human Factors Research
	3.1 Questionnaires
		Likert Scale
		Semantic Differential
		Ranking
		Constant Sum
	3.2 Biometric Research
		Eye Tracking
		Facial Expression Analysis (FEA)
		Galvanic Skin Response (GSR)
		Electroencephalography (EEG)
		Electrocardiography (ECG)
	3.3 Correlational Research
	3.4 Experiments
		The Two-Condition Experimental Design
		Multiple Condition Design
		Factorial Design
		Between Subjects and Within Subjects Designs
	3.5 Analyzing Quantitative Data
		Central Tendency
		Dispersion
	Resources
	References
Chapter 4: Usability Evaluation
	4.1 Introduction
	4.2 Usability Inspection
		Heuristic Evaluation
		Cognitive Walkthrough
	4.3 Usability Testing
		What Is Usability Testing?
		Usability Study Tips and Pitfalls
			Seven Tips for a Successful Usability Test
			Top Seven Mistakes in Usability Test
		Categories of Usability Tests
		Components of a Usability Test
			Scenarios
			Tasks
			Subtasks
		What Is Measured in a Usability Test?
		How Many Participants Do You Need for a (Formative) Usability Test?
		Training Prior to Usability Testing
		Estimating Time Needs for a Usability Test
			Internal Pilot Testing
			Plan for Extra Time During Remote Usability Testing
			“It’s an Easy to Use System (I Swear)”
			Complicated Scenario Setups
			True Pilot Test
			Plan for the Worst, Hope for the Best
		The Iceberg Paradox
		Counterproductive Outlooks About Formative Usability Testing
	Resources
	References
Chapter 5: Visual Perception
	5.1 Information Processing
	5.2 Bottom-Up and Top-Down Processes
	5.3 Light Energy and the Eye
	5.4 Rods, Cones, and Color Perception
	5.5 Color Deficiency
	5.6 Contrast
	5.7 Image Size and Visual Angle
	5.8 Visual Accommodation
	5.9 Vision Problems
	5.10 Aging and Vision
	5.11 Central and Peripheral Vision
	5.12 How Visual Perception Works
	5.13 Attention’s Role in Visual Perception
	5.14 Conspicuity
	5.15 Context
	5.16 Gestalt Psychology
		Figure-Ground
		Law of Pragnanz
		Proximity
		Continuity
		Closure
		Symmetry
		Similarity
		Common Region
		Familiarity
	5.17 Information Structure
		Visual Hierarchies
	5.18 Design Advice Based on Visual Perception
		Item Placement and Grouping
		Consistency
		Adhere to User Expectancies
		Redundant Coding
		Make Text Legible
		Contrast
		Make Sure Errors Capture the User’s Attention
		Color
	Resources
	References
Chapter 6: Hearing
	6.1 Introduction
	6.2 What Is Sound?
		The Building Blocks of Sound
			Intensity
				Intensity vs. Loudness
				Decibels vs. Loudness
				Equal-Loudness Contour
				Sound Duration and Complexity
			Frequency and Pitch
				Frequency vs. Pitch
				Sound Intensity and Pitch
				The Doppler Effect
				Noisy Signals
			Timbre
	6.3 How Do We Hear Sound?
		Outer Ear
		Middle Ear
		Inner Ear
	6.4 Sound Localization
	6.5 Hearing Impairments and Disorders
		Sensorineural Hearing Loss (SNHL)
		Conductive Hearing Loss (CHL)
		Auditory Processing Disorder (APD)
	Resources
	References
Chapter 7: Cognition
	7.1 Cognitive Resources
	7.2 Attention
		Focused Attention
		Multitasking
		Sustained Attention
	7.3 Memory
		Working Memory
			Capacity of WM
			Duration of WM
			WM and Attention
			Phonological Similarity Effect
			Serial Position Effect
			Prospective Memory
		Long-Term Memory
		Contextual Memory, Recognition and Recall
		Structure of Long-Term Memory
		Declarative vs. Procedural Knowledge
		Organization of Semantic Memory
		Categorization
		Knowledge in the World vs. Knowledge in the Head
	7.4 Tips for Designers
	Resources
	References
Chapter 8: Use-Error
	8.1 Introduction
	8.2 What Is the Cause of All of These Use-Errors?
		Size and Complexity
		Emphasizing Technology Over the User
		Feature Creep
		Assuming Users Will Become Experts
		Relying on Training
		Underestimating Environmental Challenges
		Failing to Design for the “Worst Case Scenario”
		Failing to Expect Use-Errors
		Underestimating User Diversity
		Expecting People to Multitask
		Overestimating User Capabilities and Motivation
		Failing to Involve Users Early in Design
		Excessive Reliance on Thought Leaders
		Lack of Focus on Human Factors
	8.3 Slips
		Capture Slip
		Description Similarity Slip
		Mode Error Slip
	8.4 Lapses
	8.5 Mistakes
	8.6 Root Cause Analysis
	8.7 Hindsight Bias
	8.8 Designing for Error
		Swiss Cheese Model
		Constraints
		Undo
		Sensibility Checks
	8.9 Regulatory Considerations
	Resources
	References
Chapter 9: Human Factors Regulations for Medical Devices
	9.1 Human Factors Regulatory Guidelines
	9.2 Human Factors Process for Medical Devices
		Step 1: Identify Users, Environments, and Critical Tasks
			Identify Device Users
			Device Use-Environment
			Device User Interfaces
			Known Use-Related Issues
			Critical Tasks
		Step 2: Formative Research and Design Process
			Formative Generative Research
			Formative Usability Research
		Step 3: Validation/Summative Usability Testing
			Preparing for Validation/Summative Usability Testing
			Participant Criteria for Validation/Summative Usability Testing
			Simulated Use-Environment
			Market-Ready Devices
			Participant Training
			Tasks Included in Validation Testing
			Data Collected
				Observational Data
				Knowledge Task Data
				Open-Ended Interview Data
			Analysis of Validation/Summative Usability Test Results
		How Many Use-Errors Will the FDA/Regulatory Agency Accept?
		Do We Have to Evaluate Tasks That Aren’t Critical? If So, Should Noncritical Task Results Be Included in the Report?
		How Do We Define Critical Tasks?
		How Realistic Does the Simulated-Use Environment Need to Be?
		Can We Make Changes to the Device or Instructions After the Validation Usability Study?
		What Is the Purpose of Identifying Known Issues and How Do We Identify Them?
		What Characteristics Can Be Used to Define a “User Group”?
		Can Nurses and Physicians Be Included in One User Group?
		How Do You Recommend That We Incorporate User Research into Our Design Process? How Often and When Should We Conduct User Research? What Are the Best Strategies?
		Is There a Fast and Effective Way to Get Feedback on the Usability of My Device Without Having to Do an Actual Study with Users?
	Resources
	References
Chapter 10: Controls: Designing Physical and Digital Controls
	10.1 Introduction
	10.2 Control Coding Guidelines
		Color Coding
		Size Coding
		Location Coding
		Shape Coding
		Label Coding
		Mode of Operation
	10.3 Control Movement Considerations
		Directionality Considerations
		Control Travel Considerations
		Control Gain
	10.4 Control Size and Shape Considerations
		The Size of a Control(s) Should Be Comfortable, Accurate, and Consistent Use
		Surface Area Is King
		When Possible, Reduce, or Eliminate the Need for Fine Motor Control
		Finger-Operated Controls Should Support Multifinger Use
		Textures Help Improve Suboptimal Control Shapes
		Size and Shape Should Be Scaled to Match Effort, Duration of Use, and Accuracy Requirements
		Be Mindful of Control Resolution in Multistate Controls
		Avoid Sharp Edges Along Control Surfaces
	10.5 Control Feedback Considerations
		Visual Feedback
			Account for Environmental Luminance and Color Spectrum Factors
			Use Icons When Possible
			Use Appropriately Colored Text
			Select Appropriate Font Types
			Choose Appropriate Text Size
			Make Labels Durable
			Present Visual Feedback in Close Proximity to the Control
			Use Backlighting on Nonalphanumeric Keys Only
			Use Color Sparingly
		Auditory Feedback
			Pair Auditory and Visual Feedback Together on Tasks with Low Cognitive Workload Demands (Avoid It on High-Demand Tasks)
			Minimize Auditory Feedback Duration and Intensity for Frequently Used Controls
			Avoid “Pure Tones” When Presenting Auditory Control Feedback
			Avoid Using Sound as the Only Mechanism for Control Location Feedback
	10.6 Activation Force Considerations
	10.7 Control Placement Considerations
		Mind the User’s Reach Envelope
		Dead Space Between Neighboring Controls Limit Accidental Activation
		Controls Placed Together Naturally Suggest a “Familial” Relationship
	10.8 Touchscreen Considerations
		Types of Touchscreens
			Capacitive Touchscreens
			Resistive Touchscreens
			Surface Acoustic Wave (SAW) Touchscreens
		Size Considerations
			Embrace Existing Gestures and Shortcuts
			Activate Controls on “Up” Triggers
	Resources
	References
Chapter 11: Displays
	11.1 Introduction to Displays
	11.2 Visual Displays
		Common Types of Visual Display Technologies
		Luminance Considerations
		Contrast
			Use-Environment
			User Needs
		Viewing Angle
		Hardware Considerations
		Color Considerations
		Resolution and Clarity Considerations
			Task Demands
		Shape and Size
			User Considerations
		Placement Considerations
			User Considerations
			Use-Environments
	11.3 Auditory Displays and Alarms
		Overview of Auditory Displays and Alarms
		Fundamentals of Auditory Displays
			Creating Discoverable Sounds
			Localization of Sounds
			Giving “Meaning” to Sounds
				Nonspeech Sounds
				Speech-Based Sounds
					Benefits of Speech-Based Sounds
					Drawbacks of Speech-Based Sounds
					Human-Generated Speech vs. Computer-Generated Speech
				Rate of Speech
				Vowel Spacing
				Spearcons
			Creating a Sense of Urgency
			Alarm-Specific Considerations
				Alarm Fatigue
				Category-Specific Alarm Sounds
				Dismissing and Delaying Alarms
	Resources
	References
Chapter 12: Human–Computer Interaction
	12.1 Introduction
	12.2 User Experience (UX)
	12.3 Design Principles
		Support Mental Models
		Allocate Tasks Wisely
		Consistency
		Minimize Memory Load
		Provide Informative Feedback
		Make Tasks Efficient
		Utilitarian/Minimalist Design
		Error Prevention and Error Handling
	12.4 Interaction Styles
		Form Fill-in
		Menus
		Direct Manipulation
		Command Line
		Gestures and Multitouch
		Dialog Boxes
	12.5 Information Architecture
		Depth vs. Breadth
		Serial Choice
		Branching
		Networked
	12.6 Screen Layout
		Grid
		Columns
		Blank Space
		Gutters, Margins, and Padding
		Grouping
	12.7 Legibility
		Text Size
		All Capitals
		Contrast
		Text Justification
	12.8 Color
		Color Guidelines
		Data Visualization and Graphics
		Table Design
		Small Displays
	Resources
	References
Chapter 13: Designing Instructions for Use(rs)
	13.1 Definitions
	13.2 Do We Need Instructions for Use?
	13.3 No Respect
		IFU as User Interface
		IFUs as Checking a Box
		IFUs as an Afterthought
		But Nobody Uses the IFU Anyway
		Rewriting IFU into Standard Operating Procedures (SOP)
		Ease of Use vs. Regulatory Standards
	13.4 Developing Instructions for Use(rs)
		Start Designing Early
		Develop User Profile
		Develop Environmental Profile
		Consider the User’s Tasks
		Determine the Appropriate Format
		Identify Appropriate Authors
		Consider the Regulatory Requirements
	13.5 A Framework for Developing Good IFUs and a Model of IFU Use
		Finding Information
		Signal vs. Noise
		Organization
		Comprehending Information
		Cognitive Load Theory
		Chunking
		Meaning
		Familiarity
		Conciseness
		Facilitating Learning
	13.6 Applying Information
		Sequencing
		Help Readers Save Their Place
		Provide Feedback
	13.7 IFU Iteration and Evaluation
	Resources
	References
Chapter 14: Reusable Medical Devices, Reprocessing, and Design for Maintenance
	14.1 Introduction
	14.2 Reusable Medical Devices and Designing for Maintenance
	14.3 Reprocessing and Designing for Maintenance
		What Is Reprocessing?
		Why Is Reprocessing a Human Factors Engineering Issue?
	14.4 Designing Reusable Medical Devices to Optimize Reprocessing
		Interface 1: Reusable Medical Device
		Interface 2: Reprocessing Instructions for Use
		Interface 3: Training
	14.5 Conclusion
	Resources
	References
Chapter 15: Home Healthcare
	15.1 Introduction
	15.2 Challenges of Home Use Medical Device Design
	15.3 Users of Home-Use Devices
	15.4 Physical Size, Strength, and Stamina
	15.5 Dexterity, Flexibility, and Coordination
	15.6 Sensory Capabilities (Vision, Hearing, Tactile Sensitivity)
	15.7 Cognitive Abilities
	15.8 Literacy and Language Skills
	15.9 Emotions and Motivation
	15.10 Environment
	15.11 Design Considerations
	References
Index